


Growing Up (Growing Fast)

by Lumelle



Category: Tennis no Oujisama | Prince of Tennis
Genre: Alpha Sanada Genichirou, Alpha/Beta/Omega Dynamics, Kid Fic, M/M, Omega Atobe Keigo, Past Relationship(s)
Language: English
Status: Completed
Published: 2018-06-23
Updated: 2018-06-23
Packaged: 2019-05-27 08:38:06
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,111
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15020816
Author URL: https://archiveofourown.org/users/Lumelle/pseuds/Lumelle
Summary: Sanada likes to think he is a responsible person. He certainly does his best to do his part as a father.Perhaps he doesn't have to do it alone, though.





	Growing Up (Growing Fast)

**Author's Note:**

> Basically this is a shortened version of a story I'm sloooowly working on. Since I have no idea when or if that one gets finished, I thought I'd post the shorter approach as well.

Perhaps it was arrogant of Sanada, trying to act like a grownup when it was so painfully obvious they were anything but, yet he couldn’t see any other choice he could make. When Seiichi looked at him with serious eyes in their last year of middle school and announced he was pregnant, the first thing Sanada asked was what Seiichi wanted to do, the second how he could help.

What Seiichi wanted was play tennis, as it turned out, and Sanada had no intention of standing in his way. It took some time and long conversations with both their families to come to a decision, but in the end, there was only one thing he could imagine doing.

High school started and Seiichi wasn’t there, headed abroad to start turning his passion into a career. Sanada started Rikkai High School without him, attended the first meeting of the tennis club amidst familiar faces, then headed home to the one who needed him most.

Keiichi was the most amazing thing Sanada had ever seen. Sure, he started out small and useless at anything but crying and soiling himself, but even so, his child was a wonder and Sanada was proud to be his sire. He was eternally grateful to his family for looking after Keiichi when he couldn’t, but he made a point of always taking charge the moment he got home. This was his child, his responsibility, and he wasn’t going to back away just because it was often a rather tiring and smelly task.

Of course, children didn’t stay quite so small forever, and Keiichi was no exception. With every passing day he grew and developed further, delighted Sanada with smiles and babbles just as his first teetering attempts at moving about made him fear. Somehow they both made it through the unsteady phase without broken bones or permanent trauma, and one day Sanada found a happy baby toddling to meet him at the door with a cry of Papa. He had plenty of homework and upcoming exams to worry about, but all that could wait until after he had cuddled his little miracle.

Not everything went quite as smoothly. Keiichi was awfully slow to learn more words, and no amount of assurances about how children developed at different paces would stop Sanada from reading endless guides and articles about sheech development and fretting over every missed milestone. Keiichi was a bright little tot, his parents reminded him, alert and observant though sometimes a little shy. Perhaps he just didn’t have much to say, his brother suggested, taking after his taciturn sire. After that remark Sanada even made more of an effort to speak to Keiichi at every opportunity, but it made him feel awkward and self-conscious. The last thing he wanted was for Keiichi to think speaking was something to worry about.

Keiichi was almost three when chaos entered their life in the form of Atobe Keigo. From a chance meeting at a festival Atobe seemed to immediately take an interest in Keiichi, calling regularly just to chat with the child while Sanada half-listened in the background. He wasn’t sure why exactly Atobe would be so interested in his son, certainly didn’t know why Atobe would send Keiichi birthday gifts or invite Sanada and his son both to a private pool so Keiichi could practice his swimming. He had to admit he was grateful, though. Keiichi was definitely getting more talkative, and whether that was just a part of growing up or actually Atobe’s influence, Sanada was quite happy to give his rival some credit.

Atobe explained at least some of it to Sanada one afternoon, as they both sat drinking tea while Keiichi chased after Atobe’s dog through the enormous garden. Atobe spoke of Kabaji, of a quiet little boy who was too shy and self-conscious of his awkward words to speak for himself, and how Atobe had decided to speak enough for both of them. He also spoke of how their culture still often told omegas to be quiet and demure, and how Atobe had never wished to fit that particular mould. Not that there was anything wrong with Keiichi if indeed he was just shy by nature, Atobe added, but even so it was good for him to see there was more than one way of being an omega.

Sanada watched Atobe smiling softly as he heard Keiichi shrieking with delight, and couldn’t help but wonder how many people had told Atobe to be less noisy, less outgoing, less assertive. He also wondered how much of Atobe’s boisterous personality was truly him and how much was backlash against those who would define him by his sex before his person.

What he did not allow himself to wonder was if Atobe was aware of the way his eyes sparkled like the ocean in sunlight.

Somehow, along the way, his annoying but worthy rival turned into a vital part of his and his son’s life. Keiichi looked forward to Atobe’s call every evening, which had become as much a part of their bedtime routine as pyjamas and brushing teeth. Atobe watched all of Sanada’s matches he could attend just to let Keiichi watch them through a video call, and sent one of his minions to do the same when he couldn’t make it personally. Atobe waited patiently as Keiichi tried to find the right words, never getting frustrated with him. Atobe made Keiichi smile, and more and more, Sanada found he was similing, too.

Atobe was the one watching Keiichi while a doctor told Sanada his knee would probably not make it through his last season of high school tennis, never mind anything beyond that.

He bowed out at Nationals, deciding his team needed him as the captain more than they needed him breaking mid-match. Not that it mattered either way, as they narrowly lost in the semi-finals. It was not the glorious exit he had wished for, but there was no helping it.

At least this meant he could sit with Keiichi and watch as Atobe led Hyoutei through the finals to championship. As Atobe stood triumphant after his grueling match, Sanada couldn’t help but grin at the sound of Keiichi’s cheers. He was hardly surprised when Keiichi insisted on hugging Atobe afterwards. Atobe was utterly beautiful in that moment, smiling through his exhaustion as he lifted a tired hand to comb through Keiichi’s hair as he glanced up at Sanada with glittering eyes.

Sanada was slightly surprised to realize he was kissing Atobe, but since it already happened and Atobe seemed receptive, he saw no reason not to carry on.

Keiichi deserved a loving Daddy, anyway.

**Works inspired by this one:**

  * [His Very Favorite Sanada (The Second One Is Okay, Too)](https://archiveofourown.org/works/17226170) by [Lumelle](https://archiveofourown.org/users/Lumelle/pseuds/Lumelle)




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